U.S. patent number 10,617,858 [Application Number 15/877,767] was granted by the patent office on 2020-04-14 for surgical port features with electrically conductive portions, related devices, and related methods.
This patent grant is currently assigned to Intuitive Surgical Operations, Inc.. The grantee listed for this patent is Intuitive Surgical Operations, Inc.. Invention is credited to Bryan E. Blair, Sam Crews, Michael Hurst.
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United States Patent |
10,617,858 |
Hurst , et al. |
April 14, 2020 |
Surgical port features with electrically conductive portions,
related devices, and related methods
Abstract
A surgical port includes a first end, a second end opposite the
first end, and a longitudinal axis extending through the first end
and the second end. An outer sidewall extends between the first end
and the second end. First and second channels extend through the
port from the first end to the second end. A first electrically
conductive portion extends from the first channel to the outer
sidewall, and a second electrically conductive portion extends from
the second channel to the outer sidewall. The first electrically
conductive portion provides a first electrically conductive path
between the first channel and the outer sidewall and the second
electrically conductive portion provides a second electrically
conductive path the second channel and the outer sidewall. The
second electrically conductive path is separate from the first
electrically conductive path. Devices and methods relate to
surgical ports.
Inventors: |
Hurst; Michael (San Francisco,
CA), Crews; Sam (Palomar Park, CA), Blair; Bryan E.
(Santa Clara, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
Intuitive Surgical Operations, Inc. |
Sunnyvale |
CA |
US |
|
|
Assignee: |
Intuitive Surgical Operations,
Inc. (Sunnyvale, CA)
|
Family
ID: |
63038509 |
Appl.
No.: |
15/877,767 |
Filed: |
January 23, 2018 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20180221639 A1 |
Aug 9, 2018 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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62449822 |
Jan 24, 2017 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61B
17/3423 (20130101); A61B 1/313 (20130101); A61M
39/0247 (20130101); A61B 1/00154 (20130101); A61B
18/1482 (20130101); A61B 2017/3466 (20130101); A61M
2039/0294 (20130101); A61B 34/35 (20160201); A61B
34/30 (20160201); A61M 2207/00 (20130101); A61B
2034/302 (20160201); A61B 2017/3445 (20130101); A61B
2017/00526 (20130101); A61B 2018/00077 (20130101); A61M
2039/0267 (20130101); A61M 2039/0264 (20130101); A61B
2017/3449 (20130101); A61B 17/0218 (20130101); A61M
2039/0279 (20130101) |
Current International
Class: |
A61B
1/00 (20060101); A61M 39/02 (20060101); A61B
18/14 (20060101); A61B 17/34 (20060101); A61B
1/313 (20060101); A61B 18/00 (20060101); A61B
17/00 (20060101); A61B 17/02 (20060101); A61B
34/35 (20160101); A61B 34/30 (20160101) |
Field of
Search: |
;600/114,121-123,153,204,205,206,208 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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WO-03091608 |
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Nov 2003 |
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WO |
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WO-2008103151 |
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Aug 2008 |
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WO |
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WO-2009080399 |
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Jul 2009 |
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WO |
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Other References
Vertut, Jean and Phillipe Coiffet, Robot Technology: Teleoperation
and Robotics Evolution and Development, English translation,
Prentice-Hall, Inc., Inglewood Cliffs, NJ, USA 1986, vol. 3A, 332
pages. cited by applicant.
|
Primary Examiner: Philogene; Pedro
Assistant Examiner: Comstock; David C
Attorney, Agent or Firm: Jones Robb, PLLC
Parent Case Text
RELATED APPLICATIONS
This application claims priority to Provisional U.S. Patent
Application No. 62/449,822, filed on Jan. 24, 2017, which is
incorporated by reference herein in its entirety.
Claims
What is claimed is:
1. A surgical port, comprising: a first end; a second end opposite
the first end; a longitudinal axis extending through the first end
and the second end; an outer sidewall extending between the first
end and the second end; first and second channels extending through
the port from the first end to the second end; a first electrically
conductive portion extending from the first channel to the outer
sidewall; and a second electrically conductive portion extending
from the second channel to the outer sidewall; wherein the first
electrically conductive portion provides a first electrically
conductive path between the first channel and the outer sidewall,
the second electrically conductive portion provides a second
electrically conductive path between the second channel and the
outer sidewall, and the second electrically conductive path is
separate and electrically isolated from the first electrically
conductive path at least in part by an electrically insulative
material of the surgical port.
2. The surgical port of claim 1, wherein the first electrically
conductive portion extends into the first channel beyond an
interior surface of the first channel, or the second electrically
conductive portion extends into the second channel beyond an
interior surface of the second channel, or both.
3. The surgical port of claim 1, wherein the first electrically
conductive portion extends into the first channel beyond an
interior surface of the first channel by 0.1 millimeters (0.004
inches) to 1.0 millimeter (0.04 inches), or the second electrically
conductive portion extends into the second channel beyond an
interior surface of the second channel by 0.1 millimeters (0.004
inches) to 1.0 millimeter (0.04 inches), or both.
4. The surgical port of claim 1, wherein the first channel has a
first cross section shaped to receive an imaging instrument and the
second channel has a second cross section, different from the first
cross section, shaped to receive a surgical tool.
5. The surgical port of claim 1, further comprising a third channel
extending through the port from the first end to the second end,
wherein the second electrically conductive portion extends from the
third channel to the outer sidewall.
6. The surgical port of claim 5, wherein the first channel has a
first cross-section shaped to receive an imaging device, and
wherein the second and third channels each have a second
cross-section, different from the first cross section, shaped to
receive a surgical tool.
7. The surgical port of claim 1, wherein the first electrically
conductive portion, the second electrically conductive portion, or
both the first and second electrically conductive portions each
extend longitudinally through the port to locations on opposite
sides of a midplane of the port that intersects the longitudinal
axis.
8. The surgical port of claim 1, wherein one or both of the first
and second electrically conductive portions is offset
longitudinally from a midplane of the surgical port between the
first and second ends.
9. The surgical port of claim 1, wherein the first and second
electrically conductive portions comprise an electrically
conductive composite material comprising a continuous phase of a
polymer matrix and a discontinuous phase of electrically conductive
particles.
10. The surgical port of claim 9, wherein the electrically
conductive particles are rod shaped.
11. The surgical port of claim 10, wherein the electrically
conductive particles have a length-to-diameter ratio of at least
10:1.
12. The surgical port of claim 9, wherein the continuous phase of
the polymer matrix comprises silicone rubber.
13. The surgical port of claim 9, wherein the continuous phase of
the polymer matrix exhibits a hardness ranging from 0 to 50 on the
Shore type A hardness scale.
14. The surgical port of claim 9, wherein the continuous phase of
the polymer matrix exhibits a hardness of 10 on the Shore type A
hardness scale.
15. The surgical port of claim 9, wherein the electrically
conductive composite material comprises carbon fiber in an amount
ranging from 1 volume percent to 10 volume percent.
16. The surgical port of claim 9, wherein the electrically
conductive composite material comprises carbon fiber in an amount
ranging from 0.1 weight percent to 5 weight percent.
17. The surgical port of claim 1, wherein the first channel is
electrically isolated from the second channel.
18. A method of making a surgical port, comprising: forming an
electrically insulating body with a first negative feature defining
a channel extending from a first end to a second end of the body
and with a second negative feature extending from an opening in an
inner surface of the channel to an opening in an outer sidewall of
the electrically insulating body; and forming an electrically
conductive portion within the second negative feature and extending
from the opening in the inner surface of the channel to the opening
in the outer sidewall; wherein forming the electrically conductive
portion of the surgical port within the second negative feature
comprises molding the electrically conductive portion over the
electrically insulating body.
19. The method of claim 18, wherein molding the electrically
conductive portion over the electrically insulating body comprises
molding an electrically conductive material comprising a polymer
matrix continuous phase and an electrically conductive fiber
discontinuous phase.
20. The method of claim 19, further comprising dispersing
electrically conductive fiber particles having a length-to-diameter
ratio of at least 10:1 within the polymer matrix.
21. A surgical port comprising: a body portion having a first end
and a second end; a channel defined between the first end and the
second end, the channel being sized and configured to receive a
cannula; and an electrically conductive composite material
extending from the channel through the body portion, wherein the
electrically conductive composite material comprises a continuous
phase of a polymer matrix and a discontinuous phase of electrically
conductive fiber particles having a length-to-diameter ratio of at
least 10:1.
22. The surgical port of claim 21, wherein the electrically
conductive composite material comprises fibers in an amount ranging
from 1 volume percent to 10 volume percent.
23. The surgical port of claim 21, wherein the body portion
comprises silicone rubber.
24. The surgical port of claim 21, wherein the polymer matrix
comprises silicone rubber and the electrically conductive fiber
particles comprise carbon fiber.
Description
TECHNICAL FIELD
Aspects of the present disclosure relate to surgical port features
including electrically conductive portions.
INTRODUCTION
Various surgical instruments or tools can be positioned to extend
through cannulas passing through a surgical port positioned in an
incision of a patient's body wall. Such instruments or tools may be
configured to apply electrical energy to an operating site to carry
out a surgical procedure. For example, a surgical instrument may be
configured to seal, bond, ablate, fulgurate, or perform other
treatments of tissue through the application of an electrical
current. Additionally, a surgical instrument can be an optical
instrument, such as an endoscope, positioned to extend through a
cannula inserted through the surgical port. Such surgical
instruments and tools include, without limitation, minimally
invasive surgical instruments that are manually operated or
teleoperated using computer-assisted technology. One example of a
teleoperated, computer-assisted surgical system (e.g., a robotic
system that provides telepresence) with which embodiments of the
present disclosure may be used, are the da Vinci.RTM. Surgical
Systems manufactured by Intuitive Surgical, Inc. of Sunnyvale,
Calif.
In some situations, a capacitive coupling is induced between
surgical instruments in proximity to each other by current applied
to the one or more surgical instruments by an electro-surgical
generator (e.g., electro-surgical unit (ESU)). In particular,
capacitive coupling between an optical instrument, e.g., the
endoscope, and other surgical instruments has potential to generate
a leakage current that misdirects a portion of the current
generated by the ESU, e.g., along a conductive cannula through
which another surgical instrument extends. Such capacitive coupling
may occur between multiple instruments extending through a single
port, or between multiple instruments extending through separate,
respective ports. However, because multiple instruments passing
through a single port are typically positioned close to one
another, and because capacitive coupling generally increases with
physical proximity of the instruments, the leakage current as
described above may pose a greater problem when multiple
instruments extend through a single port.
Some surgical ports are manufactured from polymer materials, such
as, for example, silicone rubber in order to provide flexibility
and durability, which may be desired to permit temporary and
elastic deformation of the port during insertion into an incision
in the patient's body wall. Such polymers are typically good
electrical insulators. However, to mitigate capacitive coupling
between instruments, it is desirable to dissipate energy from the
respective cannulas through which the instruments extend and
through the port to ground, (e.g., to the patient's body held at a
ground potential). Thus, a need exists to provide a port with the
desired flexibility and durability while also permitting
dissipation of electrical energy from the surgical instruments to
reduce or eliminate capacitive coupling between the
instruments.
SUMMARY
Exemplary embodiments of the present disclosure may solve one or
more of the above-mentioned problems and/or may demonstrate one or
more of the above-mentioned desirable features. Other features
and/or advantages may become apparent from the description that
follows.
In accordance with at least one exemplary embodiment, a surgical
port includes a first end, a second end opposite the first end, and
a longitudinal axis extending through the first end and the second
end. An outer sidewall extends between the first end and the second
end. First and second channels extend through the port from the
first end to the second end. A first electrically conductive
portion extends from the first channel to the outer sidewall, and a
second electrically conductive portion extends from the second
channel to the outer sidewall. The first electrically conductive
portion provides a first electrically conductive path between the
first channel and the outer sidewall and the second electrically
conductive portion provides a second electrically conductive path
between the second channel and the outer sidewall. The second
conductive path is separate from the first electrically conductive
path.
In accordance with at least another exemplary embodiment, a method
of making a surgical port includes forming an electrically
insulating body with a first negative feature defining a channel
extending from a first end to a second end of the body and with a
second negative feature extending from an opening in an inner
surface of the channel to an opening in an outer sidewall of the
electrically insulating body, and forming an electrically
conductive portion within the second negative feature and extending
from the opening in the inner surface of the channel to the opening
in the outer sidewall. Forming the electrically conductive portion
of the surgical port feature within the second negative feature
comprises molding the electrically conductive portion over the
electrically insulating portion.
In accordance with yet another exemplary embodiment, a surgical
port includes a body portion having a first end, a second end, and
a surgical instrument channel defined between the first end and the
second end. An electrically conductive composite material extends
from the channel through the body portion. The electrically
conductive composite material comprises a continuous phase of a
polymer matrix and a discontinuous phase of electrically conductive
particles.
Additional objects, features, and/or advantages will be set forth
in part in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
present disclosure and/or claims. At least some of these objects
and advantages may be realized and attained by the elements and
combinations particularly pointed out in the appended claims.
It is to be understood that both the foregoing general description
and the following detailed description are exemplary and
explanatory only and are not restrictive of the claims; rather the
claims should be entitled to their full breadth of scope, including
equivalents.
BRIEF DESCRIPTION OF THE DRAWINGS
The present disclosure can be understood from the following
detailed description, either alone or together with the
accompanying drawings. The drawings are included to provide a
further understanding of the present disclosure, and are
incorporated in and constitute a part of this specification. The
drawings illustrate one or more exemplary embodiments of the
present teachings and together with the description serve to
explain certain principles and operation. In the drawings,
FIG. 1 is a cross-sectional elevation view of a surgical port and
surgical instrument according to an exemplary embodiment of the
disclosure;
FIG. 2 is a perspective view of a surgical port according to
another exemplary embodiment of the disclosure;
FIG. 3 is a perspective view of the surgical port of FIG. 2 with
instrument cannulas according an exemplary embodiment;
FIG. 4 is an interior plan view of the surgical port according to
the exemplary embodiment of FIG. 2;
FIG. 5 is a detailed perspective view of the surgical port
according to the exemplary embodiment of FIG. 2;
FIG. 6 is a cross-sectional partial elevation view of a surgical
port according to another exemplary embodiment of the
disclosure;
FIG. 7 is an interior plan view of a surgical port according to
another exemplary embodiment of the disclosure; and
FIG. 8 is an interior plan view of a surgical port according to yet
another exemplary embodiment of the disclosure.
DETAILED DESCRIPTION
The present disclosure contemplates various exemplary embodiments
of surgical port features that include portions of material having
a relatively low electrical conductivity and portions of material
having relatively high electrical conductivity. In exemplary
embodiments, the portions of material having relatively low
electrical conductivity are made from a polymer, such as silicone
rubber. The portions of material having relatively low electrical
conductivity are a polymer, such as silicone rubber, with one or
more electrically conductive materials in dispersed form in the
material. Stated another way, the portions of material having
relatively low electrical conductivity are a composite material
including a continuous phase and a discontinuous phase. The
continuous phase is polymer having a relatively low electrical
conductivity, and the discontinuous phase is a material having a
relatively high electrical conductivity. In exemplary embodiments,
the discontinuous phase is comprised of particles having rod-like,
spherical, or other shapes. In one exemplary embodiment, the
discontinuous phase is carbon-fiber particles.
In exemplary embodiments, the surgical port feature is formed by an
overmolding technique in which the high-conductivity material is
molded to form the high-conductivity portion and the
low-conductivity material is molded over the high-conductivity
material. The surgical port feature optionally includes multiple
portions of high-conductivity material separated by the
low-conductivity material. In some exemplary embodiments, one or
more of the surgical instruments, when inserted in the port, are
electrically separated from one another by the low-conductivity
material of the surgical port. For example, one or more instruments
are individually electrically connected to the patient's body wall
through respective, separate portions of high-conductivity
material. Stated another way, in exemplary embodiments, the
surgical port feature includes multiple different electrical
pathways formed from internal surfaces surrounding passages in the
port to external surfaces of the port configured to contact a
patient's body wall when inserted in an incision.
Exemplary embodiments described herein may be used, for example,
with teleoperated, computer-assisted surgical systems (sometimes
referred to as robotic surgical systems) such as those described
in, for example, U.S. Patent App. Pub. No. US 2013/0325033 A1
(published Dec. 5, 2013), entitled "Multi-Port Surgical Robotic
System Architecture," U.S. Patent App. Pub. No. US 2013/0325031 A1
(published Dec. 5, 2013), entitled "Redundant Axis and Degree of
Freedom for Hardware-Constrained Remote Center Robotic
Manipulator," U.S. Pat. No. 8,852,208 (issued Oct. 7, 2014),
entitled "Surgical System Instrument Mounting," and U.S. Pat. No.
8,545,515 (issued Oct. 1, 2013), entitled Curved Cannula Surgical
System, each of which is hereby incorporated by reference in its
entirety. Further, the exemplary embodiments described herein may
be used, for example, with a da Vinci.RTM. Surgical System, such as
the da Vinci Si.RTM. Surgical System or the da Vinci Xi.RTM.
Surgical System, both with or without Single-Site.RTM. single
orifice surgery technology, all commercialized by Intuitive
Surgical, Inc. Although various exemplary embodiments described
herein are discussed with regard to surgical instruments used with
a patient side cart of a teleoperated surgical system, the present
disclosure is not limited to use with surgical instruments for a
teleoperated surgical system. For example, various exemplary
embodiments of surgical ports described herein can optionally be
used in conjunction with hand-held, manual surgical instruments,
such as laparoscopic instruments.
Referring now to FIG. 1, an exemplary embodiment of a surgical port
feature 100 according to the disclosure is shown. The surgical port
feature 100 is positioned within an incision 102 in a body wall 104
of a patient. The surgical port feature 100 includes a channel 106
extending from a first surface (e.g., a first end) 108 to a second
surface (e.g., a second end) 110 of the surgical port feature 100.
An outer sidewall 112 of the surgical port feature 100 between the
first surface 108 and the second surface 110 defines a narrowed
waist portion 114 of the surgical port feature 100. The surgical
port feature 100 includes a body portion 116 made from an
electrically insulating material. An electrically conductive
portion 118 comprising an electrically conductive material
intersects the outer sidewall 112 and an interior surface of the
channel 106, thereby forming an electrically conductive pathway
between the channel 106 and the body wall 104.
A surgical instrument 120 is positioned within a cannula 122
extending through the channel 106. The cannula 122 is made from or
includes a conductive material that forms an electrical pathway
between the surgical instrument 120 and the electrically conductive
portion 118 of the surgical port feature 100. The voltage potential
of the surgical instrument 120 is thereby equalized with the
electrical potential of the patient's body. In other words, the
surgical instrument 120 is grounded to the patient's body through
the cannula 122 and the electrically conductive portion 118 of the
surgical port feature 100.
As shown in FIG. 1, the surgical instrument 120 is an endoscope.
However, surgical instruments of any kind, such as other imaging
instruments, surgical instruments with end effectors configured to
manipulate or apply electrosurgical energy to tissue, end effectors
configured to apply staples, clips, or other articles, or other end
effectors, are considered to be within the scope of this
disclosure.
Referring now to FIGS. 2 and 3, another exemplary embodiment of a
surgical port feature 238 is shown. The surgical port feature 238
includes an upper flange 240 and a lower flange 242. The upper
flange 240 defines a first surface (e.g., first end) 241 and the
lower flange 242 defines a second surface (e.g., second end) 243
opposite the first surface 241. A narrowed waist portion 244 is
located between the upper flange 240 and the lower flange 242 and
defines an outer sidewall of the surgical port feature 238. A
longitudinal axis A.sub.L extends through the first surface 241 and
the second surface 243 of the surgical port feature 238. Channels
246, 248 (not fully visible in FIG. 2), and 250 configured to
receive cannulas are formed through the surgical port feature 238
and extend between the upper flange 240 and lower flange 242. In
use, the surgical port feature 238 is positioned in an incision in
a patient's body wall 204 so that the upper flange 240 is
positioned outside of the body wall 204, while the lower flange 242
is positioned within the body wall 204. At least a portion of the
narrowed waist portion 244 contacts the patient's body wall 204
within the incision.
One or more surgical instruments (including, e.g., the endoscope
120 of FIG. 1) can each be positioned within a respective one of
the cannulas 235, 236, and 237 extending through the channels 246,
248, and 250, respectively. In the exemplary embodiment of FIG. 3,
the cannulas 235, 236, and 237 are made from conductive material or
are otherwise configured to include a conductive path between an
interior of the cannula and an exterior surface of the cannula,
thus providing a conductive path between a surgical instrument
positioned inside the cannula and the exterior of the cannula.
When surgical instruments configured to apply electrical current to
the surgical site or instruments otherwise configured to operate
using electrical current (e.g., imaging instruments such as the
endoscope 120 of FIG. 1) are positioned within electrically
conductive cannulas extending through the port and are subsequently
energized, capacitive coupling between the instruments can result
in misdirection of electrical energy by creating a leakage current
through at least one of the conductive cannulas and the body of the
patient. Thus, it is desirable to provide a surgical port feature
238 configured to enable predictable and consistent dissipation of
an electrical current, such as a current generated by capacitive
coupling between instruments inserted through the port, to the body
ground through the material of the surgical port feature 238.
Accordingly, in the exemplary embodiment of FIGS. 2 and 3, the
surgical port feature 238 includes a body portion 256 made from a
first material exhibiting a relatively low electrical conductivity
and one or more electrically conductive portions, such as
electrically conductive portions 258, 260 made from a second
material exhibiting a relatively higher electrical conductivity.
The electrically conductive portions 258, 260 form a conductive
path between an interior surface of a channel of the surgical port
feature 238 (such as an interior surface of the one or more of
channels 246, 248, and 250) and a portion of the surgical port
feature 238 (e.g., a surface of the waist portion 244) configured
to contact the patient's body when the surgical port feature 238 is
positioned in the patient's body wall 204.
In exemplary embodiments, the first, electrically insulating
material of the surgical port feature 238 exhibits mechanical
characteristics such as a low hardness (e.g., high flexibility). As
a non-limiting example, in some exemplary embodiments, the
electrically insulating material of the surgical port feature 238
exhibits a hardness represented by a measurement of ranging from 0
to 50 on the Shore type A hardness scale. Factors for consideration
in material choice include electrical characteristics, such as
electrical resistivity, and mechanical characteristics, such as
hardness, ultimate tensile strength, or other factors. As a
specific, non-limiting example, the first, electrically insulating
material of the surgical port feature 238 exhibits a durometer
measurement of 10 on the Shore type A hardness scale. In various
exemplary embodiments, the first, electrically insulating material
of the surgical port feature 238 is silicone rubber.
The second, electrically conductive material from which the
electrically conductive portions 258, 260 are formed is a material
with mechanical characteristics similar to the first, electrically
insulating material, but which exhibits electrical conductivity
higher than the electrical conductivity of the first, electrically
insulating material. In some exemplary embodiments, the second,
electrically conductive material is silicone rubber with the
addition of one or more materials that increase the electrical
conductivity of the material. Normally, additives that increase the
electrical conductivity of the silicone rubber material can
adversely affect the mechanical properties of the silicone rubber.
For example, added conductive materials can cause the silicone
rubber to exhibit higher hardness (e.g., less flexibility) than the
silicone rubber without the added materials. It is desired to
substantially maintain the overall flexibility of the surgical port
feature 238, including the first and second electrically conductive
portions 258, 260. Accordingly, the disclosure provides embodiments
of surgical port features that include electrically conductive
portions made from materials that exhibit a relatively high level
of flexibility compared to other conductive materials.
For example, in exemplary embodiments of the disclosure, the first
and second electrically conductive portions 258, 260 are made from
a composite material having a continuous phase of silicone rubber
material and a discontinuous phase of carbon particulates dispersed
throughout the continuous phase. In exemplary embodiments, the
carbon particulates are in the form of fibers and are added to the
pre-molded silicone rubber raw materials and molded with the
silicone rubber to form the first and second electrically
conductive portions 258, 260. As additional non-limiting examples,
the fibers can optionally include nickel-plated carbon fibers,
nano-scale carbon materials such as carbon nanotubes, and other
similar materials.
In some exemplary embodiments, carbon fiber rods prior to mixing
have a length of several millimeters (mm), such as ranging from 1
mm to 20 mm, and a diameter of several micrometers (.mu.m), such as
ranging from 5 .mu.m to 15 .mu.m. In one exemplary embodiment, the
carbon fiber rods have a length of 12-13 mm prior to mixing and a
diameter of 10 .mu.m. As further non-limiting examples, the carbon
fiber rods before mixing with the silicone rubber raw materials
exhibit a length to diameter ratio of greater than 5:1, greater
than 10:1, greater than 20:1, greater than 50:1, greater than
100:1, etc.
As a non-limiting example, the carbon fiber rods exhibit a tensile
strength of greater than 1000 MPa (145,000 psi). As a more specific
non-limiting example, the carbon fiber rods exhibit a tensile
strength of 1207 MPa (175000 psi). In some embodiments, the tensile
strength may exceed 3000 MPa, 4000 MPa, or more. According to an
exemplary embodiment, the carbon fiber rods exhibit a tensile
modulus (i.e., elastic modulus under tensile stress conditions) of
greater than 100 GPa (14,500 kpsi). For example, in an exemplary
embodiment, the carbon fiber rods exhibit a tensile modulus of 137
GPa (20,000 kpsi). In some embodiments, the tensile modulus may
exceed 175 GPa, 200 GPa, or more.
According to various exemplary embodiments, the carbon fiber rods
are mixed with the silicone rubber raw materials at a volume
percent ranging from 1 volume percent (vol %) to 10 vol %, for
example from 4 vol % to 5 vol %. In some exemplary embodiments, the
carbon fiber rods are mixed with the silicone rubber raw materials
at a weight percent ranging from 0.1 weight percent (wt %) to 5 wt
%, for example the weight percent can be 1.5 wt %.
The weight or volume percent of carbon fiber added to the silicone
rubber is dependent at least partly on the tensile modulus of the
carbon fibers. Stronger carbon fibers (e.g., those with a higher
tensile modulus) are less likely to break during mixing with the
silicone rubber raw materials, resulting in longer lengths of
carbon fiber rods in the final molded component. This can result in
more ready formation of electrically conductive networks with one
another and result in enhanced overall electrical conductivity of
the final component for a given weight or volume percent of the
carbon fiber rods. Conversely, weaker carbon fiber rods break into
smaller lengths during mixing and do not form conductive networks
with one another as readily due to their shorter length, and
thereby can result in relatively lower electrical conductivity for
a given weight or volume percent, as compared to a stronger carbon
fiber. Sufficient tensile modulus, such as the ranges of tensile
modulus values noted above, and sufficient starting length of the
carbon fiber rods can help to ensure that the carbon fiber rods
maintain, on average, a length of greater than 1 mm, or greater
than 3 mm, greater than 5 mm, etc. In exemplary embodiments, the
carbon fiber rods exhibit an average post-mixing length ranging
from 6 mm to 12 mm.
Carbon fibers suitable for use in disclosed exemplary embodiments
are available from suppliers such as, for example, Toho Tenax
America, Inc., Rockwood, Tenn., USA; Cytec Industries Inc.,
Woodland Park N.J., USA; and Asbury Carbons, Asbury, N.J., USA.
Some carbon fibers are supplied with sizing treatments (i.e., a
chemical coating over the fiber that improves bonding of the fiber
with the resins or other polymers typically used in carbon fiber
composite materials) that may potentially interfere with (e.g.,
reduce) the electrical conductivity between the carbon fiber rods
once the carbon fiber rods are incorporated into the silicone
rubber material. Accordingly, in some exemplary embodiments, any
sizing present on the carbon fiber rods is removed from the rods
prior to mixing with the silicone rubber material to promote
electrical conductivity between the carbon fiber rods. For example,
the carbon fiber rod particles are immersed in a solvent under low
pressure conditions (e.g., within a vacuum chamber) to remove the
sizing.
In exemplary embodiments, the surgical port feature 238 is formed
using injection molding in a two-step process. The body portion 256
of the surgical port feature 238 is first injection molded from a
material having strength, elasticity, and other material
characteristics as discussed above, such as, for example, silicone
rubber. The body portion 256 includes negative portions (i.e.,
areas devoid of material) where the first and second conductive
portions 258, 260 are to be located. Following molding of the body
portion 256, the first and second conductive portions 258, 260 are
overmolded in the negative portions of the body portion 256 with
electrically conductive material, such as silicone rubber with the
addition of carbon fiber rods, as discussed above. While injection
molding is specifically mentioned, any other suitable manufacturing
processes are considered as within the scope of the disclosure. For
example, surgical ports according to exemplary embodiments of the
disclosure optionally are manufactured by casting, additive and/or
subtractive processes, other processes, and combinations
thereof.
As shown in FIG. 2, the first and second electrically conductive
portions 258, 260 extend between an interior surface of one or more
of the channels 246, 248, 250 and an outer surface of the surgical
port feature 238 proximate the waist portion 244 of the surgical
port feature 238. The first and second electrically conductive
portions 258, 258 made from the electrically conductive material
are located and configured to form an electrically conductive path
between a cannula of a surgical instrument (e.g., any one of
cannulas 235, 236, and 237 in FIG. 3) and the body wall of the
patient. For example, contact between the cannula and the
electrically conductive portion 258, 260 within one of the channels
246, 248, 250 forms a path for dissipation of electrical current
from a surgical instrument positioned within the cannula to the
patient body potential (e.g., reference potential, ground, etc.).
In some exemplary embodiments, the electrically conductive portions
are configured to form separate electrically conductive paths for
one or more of the instruments associated with each cannula (e.g.,
each of cannula 235, 236, and 237 in FIG. 3), as discussed
below.
For example, referring now to FIG. 4, a plan view of the surgical
port feature 238 according to the exemplary embodiment of FIG. 2 is
shown. The surgical port feature 238 includes an electrically
insulative body portion 256 and two electrically conductive
portions 258, 260 shown by hidden lines. The two electrically
conductive portions 258, 260 intersect channels 246, 248, 250
formed between the upper flange 240 and the lower flange 242 of the
surgical port feature 238, through which passages the cannulas 235,
236, and 237 may respectively be positioned (as shown in FIG.
3).
In some embodiments, due to differing electrical operational
characteristics between the surgical instruments and the endoscope,
it is desirable to electrically isolate the endoscope (e.g., an
endoscope positioned within the endoscope cannula 237 shown in FIG.
3) from the instruments (e.g., instruments positioned within
instrument cannulas 235, 236 shown in FIG. 3). As shown in FIG. 4,
the first electrically conductive portion 258 intersects channels
246 and 248, and the second electrically conductive portion 260
intersects channel 250. In the embodiment of FIG. 4, the channels
246 and 248 are configured to accept cannulas 235, 236 associated
with surgical instruments, while the channel 250 is configured to
accept cannula 237 associated with an imaging device such as an
endoscope. The first electrically conductive portion 258 is
separated from the second electrically conductive portion 260 by
portions of the electrically insulating material of the body
portion 256, thereby electrically insulating the first and second
electrically conductive portions 258 and 260 from one another.
In order to ensure consistent and secure contact between the
cannulas 235, 236, and 237 (FIG. 3) with the respective
electrically conductive portions 258, 260, the electrically
conductive portions 258, 260 optionally extend partly into one or
more of the channels 246, 248, and 250 beyond a surface of the
channel(s) that is defined by the body portion 256. In other words,
the electrically conductive portions 258, 260 are configured to
form an interference fit within the channels 246, 248, 250 with a
respective one of the cannulas 235, 236, and 237. For example,
referring to FIG. 5, channel 250 is shown in a perspective,
enlarged view of the port 238. A portion of the second electrically
conductive portion 260 extends into the channel 250 beyond a
surface of the channel defined by the body portion 256 to provide
secure contact with the cannula 237 (FIG. 3) and ensure electrical
conductivity between the cannula 237 and the second conductive
portion 260. Similarly, the first electrically conductive portion
258 (not shown in FIG. 5) may extend into the channels 246, 248
(FIG. 4) to ensure secure contact and electrical conductivity
between the cannulas 235, 236 (FIG. 3) and the first electrically
conductive portion 258.
In exemplary embodiments, the first and second electrically
conductive portions 258, 260 extend into the channels 246, 248 and
250 by 1 millimeter (0.04 inches) or less past the surface of the
channels formed by the body portion 256. As a non-limiting example,
the first and second electrically conductive portions 258, 260
extend into the channels 246, 248 and 250 by 0.5 millimeters (0.02
inches) or less. As a further non-limiting example, the first and
second electrically conductive portions 258, 260 extend into the
channels 246, 248, and 250 by 0.254 mm (0.010 inches). As another
non-limiting example, the first and second electrically conductive
portions 258, 260 extend into the channels 246, 248, and 250 by 0.1
millimeter (0.004 inches) to 1.0 millimeter (0.04 inches). However,
other configurations are contemplated, such as one or both of the
first and second electrically conductive portions 258, 260
extending into the channels 246, 248, 250 by less than 0.254
millimeters or by greater than 1 millimeter.
In some exemplary embodiments, the location and shape of the
electrically conductive portions is asymmetrical between the upper
flange and lower flange of the surgical port. For example, as shown
in FIG. 6, a surgical port feature 638 includes a body portion 656
made from an electrically insulating material, and an electrically
conductive portion 658 made from an electrically conductive
material, such as the electrically conductive material described
above. The electrically conductive portion 658 includes first and
second protrusions 662 and 664 that extend into channel 646 to
contact the cannula 635 above and below a center of motion of the
cannula 635 positioned along line 665. In an exemplary embodiment,
the line 665 falls on a midplane of the surgical port feature 638
between the upper flange 640 and the lower flange 642. Providing
points of contact above and below the center of motion of the
cannula 635 can help to ensure that the electrically conductive
portion 658 remains in contact with the cannula 635 during
articulation of the cannula 635 about the center of motion.
While the use of carbon fiber rods for imparting electrical
conductivity to the electrically conductive portion 658 as
described above results, in some embodiments, in the electrically
conductive portion 658 having flexibility similar to the
flexibility of the body portion 256, other mechanical
characteristics of the material may be altered from the material of
the body portion 656. For example, in some exemplary embodiments,
presence of the carbon fiber rods potentially affects the tensile
strength of the continuous phase material (e.g., silicone rubber)
of the electrically conductive portion 658. Additionally, excessive
manipulation (e.g., deformation) of the electrically conductive
portion 656 could potentially cause the electrically conductive
portion to tear or otherwise separate from the body portion 656
under certain conditions, or could lead to tearing within the
electrically conductive portion 656.
Accordingly, in the embodiment of FIG. 6, the electrically
conductive portion 658 is located between an upper flange 640 and
lower flange 642 of the surgical port feature 238. Because the
amount of movement of the cannula 635 for a given articulation
increases with distance from the center of motion, the electrically
conductive portion 658 is optionally located proximate the center
of motion (e.g., the line 665) to minimize deformation of the
electrically conductive portion 658 resulting from articulation of
the cannula 635.
Additionally, in some exemplary embodiments, the electrically
conductive portion 658 is optionally offset in an axial direction
(e.g., a direction extending between the upper flange 640 and lower
flange 642) toward the upper flange 640 of the surgical port
feature 638 to reduce deformation to the electrically conductive
portion 658 during insertion of the surgical port feature 638 into
an incision in the patient's body. For example, during some
surgical procedures, a surgeon or other operating room staff may
use a clamp to laterally flatten the lower flange 642 for insertion
of the lower flange 642 in an incision in the patient's body wall
(e.g., body wall 204 shown in FIG. 3). The offset of the
electrically conductive portion 658 in an axial direction toward
the upper flange 640 as shown in the embodiment of FIG. 6 reduces
the deformation occurring in the electrically conductive portion
658 and thereby potentially reduces the likelihood of damage to the
electrically conductive portion 658 during insertion of the lower
flange 642 of the surgical port feature 638.
Referring now to FIG. 7, another exemplary embodiment of a surgical
port feature 738 is shown. In the embodiment of FIG. 7, the
surgical port feature 738 includes a body portion 756 made from an
electrically insulating material. The surgical port feature 738
further includes a first electrically conductive portion 758, a
second electrically conductive portion 759, and a third
electrically conductive portion 760, all shown by hidden lines.
Each of the electrically conductive portions 758, 759, and 760 are
electrically isolated from one another by the electrically
insulating material of the body portion 756. Each of electrically
conductive portions 758, 759, and 760 intersects a respective one
of the channels 746, 748, and 750. Thus, cannulas inserted into
each of the channels 746, 748, and 750, and instruments within each
cannula, are electrically isolated from one another by the material
of the body portion 756 of the port 738 and individually and
separately grounded to the patient's body by a respective one of
the electrically conductive portions 758, 759, and 760.
In some exemplary embodiments, there is no need to isolate the
various instruments from one another as in the exemplary embodiment
of FIG. 7. Thus, in yet other exemplary embodiments, all the
channels of a surgical port may be intersected by a single
electrically conductive portion, thereby grounding all instruments
to body ground together. For example, referring now to FIG. 8, an
exemplary embodiment of a surgical port feature 838 includes a
conductive portion 858 (shown by hidden lines) that intersects all
three channels 846, 848, and 850. The conductive portion 858
creates a common ground path between the channels (and any cannulas
or instruments inserted therein) and the body of the patient. Such
an embodiment can be used in situations where there is no need to
isolate the various instruments from one another. For example, when
the various instruments have similar electrical operational
characteristics, grounding the various instruments through a common
ground path potentially does not lead to capacitive coupling
between the instruments, and the surgical port feature 838 with the
single conductive portion 858 could be used in such a
situation.
Various exemplary embodiments of the present disclosure provide
surgical port features having the capability of dissipating
electrical energy to a reference electrical potential (e.g., body
ground, "zero" voltage, etc.) while maintaining flexibility to
facilitate insertion of the surgical port feature within the
patient's body and facilitate articulation of cannulas placed
within channels of the port feature, while maintaining good
electrical contact with the cannulas.
This description and the accompanying drawings that illustrate
exemplary embodiments should not be taken as limiting. Various
mechanical, compositional, structural, electrical, and operational
changes may be made without departing from the scope of this
description and the invention as claimed, including equivalents. In
some instances, well-known structures and techniques have not been
shown or described in detail so as not to obscure the disclosure.
Like numbers in two or more figures represent the same or similar
elements. Furthermore, elements and their associated features that
are described in detail with reference to one embodiment may,
whenever practical, be included in other embodiments in which they
are not specifically shown or described. For example, if an element
is described in detail with reference to one embodiment and is not
described with reference to a second embodiment, the element may
nevertheless be claimed as included in the second embodiment.
For the purposes of this specification and appended claims, unless
otherwise indicated, all numbers expressing quantities,
percentages, or proportions, and other numerical values used in the
specification and claims, are to be understood as being modified in
all instances by the term "about," to the extent they are not
already so modified. Accordingly, unless indicated to the contrary,
the numerical parameters set forth in the following specification
and attached claims are approximations that may vary depending upon
the desired properties sought to be obtained. At the very least,
and not as an attempt to limit the application of the doctrine of
equivalents to the scope of the claims, each numerical parameter
should at least be construed in light of the number of reported
significant digits and by applying ordinary rounding
techniques.
It is noted that, as used in this specification and the appended
claims, the singular forms "a," "an," and "the," and any singular
use of any word, include plural referents unless expressly and
unequivocally limited to one referent. As used herein, the term
"include" and its grammatical variants are intended to be
non-limiting, such that recitation of items in a list is not to the
exclusion of other like items that can be substituted or added to
the listed items.
Further, this description's terminology is not intended to limit
the invention. For example, spatially relative terms--such as
"beneath", "below", "lower", "above", "upper", "proximal",
"distal", and the like--may be used to describe one element's or
feature's relationship to another element or feature as illustrated
in the figures. These spatially relative terms are intended to
encompass different positions (i.e., locations) and orientations
(i.e., rotational placements) of a device in use or operation in
addition to the position and orientation shown in the figures. For
example, if a device in the figures is turned over, elements
described as "below" or "beneath" other elements or features would
then be "above" or "over" the other elements or features. Thus, the
exemplary term "below" can encompass both positions and
orientations of above and below. A device may be otherwise oriented
(rotated 90 degrees or at other orientations) and the spatially
relative descriptors used herein interpreted accordingly.
Further modifications and alternative embodiments will be apparent
to those of ordinary skill in the art in view of the disclosure
herein. For example, the devices and methods may include additional
components or steps that were omitted from the diagrams and
description for clarity of operation. Accordingly, this description
is to be construed as illustrative only and is for the purpose of
teaching those skilled in the art the general manner of carrying
out the present teachings. It is to be understood that the various
embodiments shown and described herein are to be taken as
exemplary. Elements and materials, and arrangements of those
elements and materials, may be substituted for those illustrated
and described herein, parts and processes may be reversed, and
certain features of the present teachings may be utilized
independently, all as would be apparent to one skilled in the art
after having the benefit of the description herein. Changes may be
made in the elements described herein without departing from the
spirit and scope of the present teachings and following claims.
It is to be understood that the particular examples and embodiments
set forth herein are non-limiting, and modifications to structure,
dimensions, materials, and methodologies may be made without
departing from the scope of the present teachings.
Other embodiments in accordance with the present disclosure will be
apparent to those skilled in the art from consideration of the
specification and practice of the invention disclosed herein. It is
intended that the specification and examples be considered as
exemplary only, with the following claims being entitled to their
fullest breadth, including equivalents, under the applicable
law.
* * * * *